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3 Sheets--Sheet 2'.

R K AA SR PB Y m L R M 0 M 0 w No. 537,562. Patented Apr. 16, 1895..

3 Sheets-Sheet s. (No Model.) B PSAL,

RAILWAY BRAKE. No. 537,562. Patented Apr. 16, 1895.

W. ZILVEILZO) 1. Ines: s

THE Norms nnzns co. rnOTG-UTHQ, WASHINGTON, n, cy

FRANCOIS CHAPSAL, OF PARIS, FRANCE.

RAILWAY-BRAKE.

SPECIFICATION forming part of Letters Patent No. 537,562, dated April16, 1895.

Application filed August 20, 1 894- Serial No. 520,825. (No model.)Patented in France January 4, 1893, No. 226,918.

France, No. 226,918, have been obtained under date of January 4, 1893,)of which the following is a specification.

This invention relates to improvements in automatic compressed airbrakes and has for its object to render them adjustable at will andtoutilize the working pressure in a very efficient manner.

A continuous automatic brake system working with compressed air to beefficient in op- .eration must be capable of reducing the speed of thetrain when descending inclines and of effecting a stop at the stationswithout jerking by means of a gradually increased application of thebrakes.

The various systems now in use of continuous brakes working withcompressed air do not effectually accomplish this result.

The object of my invention is to construct an improved brake which shallhave the same power as the most rapidly acting brakes, by reducing thepressure in the main-pipe or conduit corresponding to the maximumbraking effect of these latter brakes, and shall be adjustable from thetime at which it is put into operation to the time when it gives themaximum braking effect.

In order that my said invention may be fully understood I shall nowproceed more particularly to describe the same and for that purposeshall refer to the several figures on the annexed sheet of drawings thesame numerals of reference indicating corresponding parts in all theviews.

Figure 1 is an elevation of the operating mechanism of an automaticbrake operated by compressed air with a moderator or governor inaccordance with my improved system. Fig. 2 is a transverse section ofthe same made on the line A B Fig. 1. Fig. 3 is a plan thereof. Fig. 4is a longitudinal section of r the moderator or governor taken on theline O D Fig. 5, and Fig. 5 is an end view ofthe said governor 0rmoderator. Fig. 6 shows in longitudinal section drawn to a larger scaleated by compressed air has a triple valve or distributing device of anydesired construction, an auxiliary reservoir and a brake cylinder, butthe arrangement of the difierent parts of the brake and the use of aspecial moderator or governor on the brake cylinder allow of a greatrange of adj ustability. A piston or pistons 2 connected to the brakegear according to the arrangement of the latter works or work in thebrake cylinder I (Figs. 1, 2, 3 and 6). To an auxiliary reservoir 3 isscrewed or otherwise fixed by a strap the easing 4 of a triple valve ordistributor which thus is in direct communication with the auxiliaryreservoir. A bushing 5 of the triple valve or of the distributercommunicates with a moderator or governor 6 by a pipe 7 on which isarranged a blow off valve 8.

The moderator or governor is secured on the brake cylinder 1 and has forits object to produce the adjustability of the brake through a greatrange of initial pressure and as it constitutes the most important partof my invention its construction and operation will now be more fullydescribed.

Two diaphragms-Q and 10 of different diameters are mounted on a rod 11of comparatively large diameter and formed of several parts screwedtogether and hollowed out for part of their length so as to form apassage therein.- One end of this rod constitutes a check valve and theother end is fixed to a third diaphragm 13 whose flexible part has anarea equal to that of the smallest diaphragm 9 of the two formerdiaphragms diminished by the area of the seat of the valve 12. Thegovernor or moderator is connected at one of its sides or ends to a mainpipe or conduit 16 by a union 14 and a pipe 15 while the other end issecured on the brake cylinder 1. A valve arranged say at the side 17 andopening outwardly permits of the direct escape of the air from the brakecylinder by the triple valve or by the distributor or it may be by thedischarge valve 8.

The following is a description of the working of the various parts ofthe apparatus.

If the air be compressed in the main pipe or conduit 16 the piston 18 ofthe triple valve or of the distributer is driven to the inner end of itstravel. The air then passes to the auxiliary reservoir and allcommunication in the direction of the brake cylinder 1 is stopped theair can then only enter the brake cylinder,

by passing through the moderator 6.

There are two cases to be considered: first, that in which the brake isapplied partially, for instance when descending an inclineor when agradual increased application of the brake is desired for stopping atsome prearranged station or the like on the line, and, secondly, when asudden stop is necessary in case of danger. In the first case, beforethe brakes have been applied, as the pressure of air in the main pipe orconduit acts alone 011 the diaphragm 13 of the moderator or governor,the check valve 12 which shuts off communication with the brake cylinderremains on its seat. If a slight reduction of pressure be produced inthe main pipe or conduit but sufficient to set in motion the piston ofthe triple valve or of the distributor, the air in the reservoir 3 willact on the diaphragm 9 of the moderator or governor. The apparatus thenmoves away from the valve seat since the pressure of the air in theauxiliary reservoir 3 is at this moment greater than that of the air inthe main pipe or conduit 16 and the check valve 12 opens leaving apassage for the air from the auxiliary reservoir 3. A certain amount ofair then passes at the same time into the brake cylinder 1 and by thecentral passage in the rod 11 carrying the check valve into the chamberformed between the large diaphragm 10 and the diaphragm 13 of themoderator with the result, well known with differential pistons, thatthe apparatus is moved in the direction of the large diaphragm by aforce equal to the pressure of air in this chamber acting on an areaequal to the difference between the area of the large diameter diaphragm10 and 'the flexible part of the other said diaphragm 13. This force isadded to that which the pressure of the air of the main pipe or conduitexerts on the other side or face of the diaphragm in order to oppose themovement in a contrary direction resulting from the pressure of air inthe auxiliary reservoir on the small diaphragm 9. Now if the differencesbetween the surfaces of the large diaphragm 10 and of the diaphragm 13 1be equal to of the surface of the diaphragm 13 and we suppose that thepressure in the auxiliary reservoir remains constant at the commencementof the application of the brakes then the equation of equilibrium of theapparatus composed of the valve 12 and the diaphragms connectedtherewith, taking no ac- 1 count of friction, will be 6 f, 6 being thereduction of pressure in the main cond uit or pipe andf the resultingpressure in the brake cylinder, 212., the valve 12 will close (or be inequilibrium and ready to close) when the pressure in the brake cylindershall equal 12 times the diminution of pressure produced in the mainconduit or pipe, the maximum braking pressure being obtained when suchdiminution of 1 pressure equals 5 of the pressure 1n the auxiliaryreservoir. Thus by giving different values to n the range of the initialpressure through which the brake will be controlled can be made to varyas desired, every reduction of pressure in the main conduit or pipegiving a pressure equal to n times this reduction of pressure in thebrake cylinder until the pressure in the latter will be equal to thepressure corresponding to the expansion of the air in the auxiliaryreservoir into the sum of the volumes of this reservoir and of the brakecylinder. In practice, however, the pressure in the auuiliary reservoirdoes not remain constant at the initial pressure, but diminishes byreason of the escape of the air therefrom into the braking cylinder.Consequently to get the maximum braking effect the reduction in the mainconduit must equal the sum obtained by adding the amount of 1 thisdiminution to of the final pressure in the auxiliary reservoir and brakecylinder.

It will thus be perceived that the valve 12, for controlling the supplyof air to the brake cylinder, is self opening under a force which iscounteracted by the joint effects of the air pressures in the brakecylinder and main pipe or conduit, respectively. By lightly reducing themain pipe pressure the brakes may be applied gently. By graduallyvarying the main pipe pressure, the brakes may be applied with graduallychanging pressure to any desired extent within (of course) the limits ofthe air supply. In the second case when a sudden stop is to be made, itis only necessary to produce quickly a large-reduction of the pressurein the main conduit, so that the pressure tending to open the valve isopposed entirely or almost so by the less potent pressure within thebrake cylinder, and the moderator presents no obstacle to a rapid andheavy increase of the braking pressure.

The moderator or governor which has already been described may beapplied without IOC IIC

any alteration of the apparatus to any continuous brake working withcompressed air with rapid action in which it is desired to avoid thecomplete application of the brakes when descending an incline, or thesudden jerks so disagreeable to travelers when stopping at stations ifthe brake be not gradually applied. When the pressure in the mainconduit is restored for relieving or removing the brakes the check valveof the moderator remains closed, because the triple valve or thedistributer then places the pipe 7 and consequently also the pressurechamber formed (in part) by the small diaphragm in comm unication withthe outside air, so that the pressure against diaphragm 13 holds thecheck valve closed, the air of the brake cylinder escaping directly bythe side valve 17 hereinbefore referred to.

In the application of the moderator to the brake apparatus, it is animportant advantage to have such an arrangement as that the working ofthe moderator can be started or interrupted without interfering with theordinary working of the brake apparatus. Thus as shown the union orbranch pipe ltconstitutes a main conduit connection for the moderatorseparate from that for the triple valve or distributer, and is providedwith a stop-cock14 having a drainage hole 14 in the casing and a properhole in the plug or key for allowing the air in the pressure chamber ofthe diaphragm 13 to escape when the cock is turned to interrupt theconnection. Such cocks are well known.

When the working of the moderator is stopped by closing the cock l t,the air will pass from the auxiliary reservoir into the brake cylinderwhenever the triple valve or distributer opens the communication throughthe pipe 7; for the pressure of the air from the auxiliary reservoirupon the diaphragm 9 (being unopposed by the pressure in the main pipe16) opens the check valve 12 and keeps it open.

By adjusting the cock l t the brakes on the different cars can beadjusted according to the length of the train and the position of thecars therein. Thus by the cooks 14' the flow of air through the pipes 14of the different cars can be checked to a degree which corresponds withthe nearness of the respective cars to the engine, with the result thatwhen pressure in the main conduit 16 is reduced by the engineer in orderto apply the brakes, such reduction reaches the different cars insuccession according to their respective distances from the engine, butthe reduction in pressure in the moderators being checked by the cocks14 in the opposite sense, (that is, being most checked in the carsnearest the engine) the brakes are applied simultaneously (or morenearly so) and violent jolts are avoided.

Having now particularly described and as certained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. The combination with the main conduit, brakecylinder, and auxiliary reservoir, of a triple valve or distributerhaving pipe connections severally with the said conduit and cylinder andreservoir, and a moderator having a valve to control the pipe connectionbetween the said triple valve or distributer and said brake cylinder andalso having three pressure chambers whose movable diaphragms areconnected with said valves, one of said pressure chambers communicatingwith the pipe connection from the said triple Valve distributer to thesaid brake cylinder, a second with the interior of said cylinder, andthe third with the main conduit, substantially as described.

2. The combination with the brake cylinder, air-supplying means, andmain conduit of a moderator composed of a valve and three pressurechambers whose movable diaphragms are connected with said valve, one ofsaid chambers being formed between oppositely acting diaphragms ofdifierentareas and communicating with theinterior of the brake cylinder,a second of said pressure chambers communicating with the air supplypipe for said cylinder, the third communicating with the main conduit,and the diaphragms of the several chambers being arrangedso that thepressures in the first and third chambers act with each other and inopposition to the press ure in said second chamber, substantially asdescribed.

3. The combination of the brake cylinder, main conduit, triple valve ordistributor, auxiliary reservoir, moderator having a valve to controlthe pipe connection between the triple valve or distributer and thebrake cylinder, and also having a pressure chamber connected with saidmain conduit independently of said triple valve or distributor, and astop cock or valve between the said pressure chamber and the mainconduit, substantiallyas described.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

FRANQOIS CHAPSAL. Witnesses:

GEORGES DELOY, CLYDE SHROPSHIRE.

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